git.sesse.net Git - ffmpeg/blob - libavfilter/avfiltergraph.c

   1 /*
   2  * filter graphs
   3  * Copyright (c) 2008 Vitor Sessak
   4  * Copyright (c) 2007 Bobby Bingham
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include <ctype.h>
  24 #include <string.h>
  25
  26 #include "avfilter.h"
  27 #include "avfiltergraph.h"
  28 #include "internal.h"
  29
  30 #include "libavutil/log.h"
  31
  32 static const AVClass filtergraph_class = {
  33     .class_name = "AVFilterGraph",
  34     .item_name  = av_default_item_name,
  35     .version    = LIBAVUTIL_VERSION_INT,
  36 };
  37
  38 AVFilterGraph *avfilter_graph_alloc(void)
  39 {
  40     AVFilterGraph *ret = av_mallocz(sizeof(AVFilterGraph));
  41     if (!ret)
  42         return NULL;
  43 #if FF_API_GRAPH_AVCLASS
  44     ret->av_class = &filtergraph_class;
  45 #endif
  46     return ret;
  47 }
  48
  49 void avfilter_graph_free(AVFilterGraph **graph)
  50 {
  51     if (!*graph)
  52         return;
  53     for (; (*graph)->filter_count > 0; (*graph)->filter_count--)
  54         avfilter_free((*graph)->filters[(*graph)->filter_count - 1]);
  55     av_freep(&(*graph)->scale_sws_opts);
  56     av_freep(&(*graph)->filters);
  57     av_freep(graph);
  58 }
  59
  60 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
  61 {
  62     AVFilterContext **filters = av_realloc(graph->filters,
  63                                            sizeof(AVFilterContext*) * (graph->filter_count+1));
  64     if (!filters)
  65         return AVERROR(ENOMEM);
  66
  67     graph->filters = filters;
  68     graph->filters[graph->filter_count++] = filter;
  69
  70     return 0;
  71 }
  72
  73 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
  74                                  const char *name, const char *args, void *opaque,
  75                                  AVFilterGraph *graph_ctx)
  76 {
  77     int ret;
  78
  79     if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
  80         goto fail;
  81     if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
  82         goto fail;
  83     if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
  84         goto fail;
  85     return 0;
  86
  87 fail:
  88     if (*filt_ctx)
  89         avfilter_free(*filt_ctx);
  90     *filt_ctx = NULL;
  91     return ret;
  92 }
  93
  94 int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
  95 {
  96     AVFilterContext *filt;
  97     int i, j;
  98
  99     for (i = 0; i < graph->filter_count; i++) {
 100         filt = graph->filters[i];
 101
 102         for (j = 0; j < filt->input_count; j++) {
 103             if (!filt->inputs[j] || !filt->inputs[j]->src) {
 104                 av_log(log_ctx, AV_LOG_ERROR,
 105                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
 106                        filt->input_pads[j].name, filt->name, filt->filter->name);
 107                 return AVERROR(EINVAL);
 108             }
 109         }
 110
 111         for (j = 0; j < filt->output_count; j++) {
 112             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
 113                 av_log(log_ctx, AV_LOG_ERROR,
 114                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
 115                        filt->output_pads[j].name, filt->name, filt->filter->name);
 116                 return AVERROR(EINVAL);
 117             }
 118         }
 119     }
 120
 121     return 0;
 122 }
 123
 124 int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
 125 {
 126     AVFilterContext *filt;
 127     int i, ret;
 128
 129     for (i=0; i < graph->filter_count; i++) {
 130         filt = graph->filters[i];
 131
 132         if (!filt->output_count) {
 133             if ((ret = avfilter_config_links(filt)))
 134                 return ret;
 135         }
 136     }
 137
 138     return 0;
 139 }
 140
 141 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
 142 {
 143     int i;
 144
 145     for (i = 0; i < graph->filter_count; i++)
 146         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
 147             return graph->filters[i];
 148
 149     return NULL;
 150 }
 151
 152 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 153 {
 154     int i, j, ret;
 155     int scaler_count = 0;
 156     char inst_name[30];
 157
 158     /* ask all the sub-filters for their supported media formats */
 159     for (i = 0; i < graph->filter_count; i++) {
 160         if (graph->filters[i]->filter->query_formats)
 161             graph->filters[i]->filter->query_formats(graph->filters[i]);
 162         else
 163             avfilter_default_query_formats(graph->filters[i]);
 164     }
 165
 166     /* go through and merge as many format lists as possible */
 167     for (i = 0; i < graph->filter_count; i++) {
 168         AVFilterContext *filter = graph->filters[i];
 169
 170         for (j = 0; j < filter->input_count; j++) {
 171             AVFilterLink *link = filter->inputs[j];
 172             if (link && link->in_formats != link->out_formats) {
 173                 if (!avfilter_merge_formats(link->in_formats,
 174                                             link->out_formats)) {
 175                     AVFilterContext *scale;
 176                     char scale_args[256];
 177                     /* couldn't merge format lists. auto-insert scale filter */
 178                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 179                              scaler_count++);
 180                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
 181                     if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
 182                                                             inst_name, scale_args, NULL, graph)) < 0)
 183                         return ret;
 184                     if ((ret = avfilter_insert_filter(link, scale, 0, 0)) < 0)
 185                         return ret;
 186
 187                     scale->filter->query_formats(scale);
 188                     if (((link = scale-> inputs[0]) &&
 189                          !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
 190                         ((link = scale->outputs[0]) &&
 191                          !avfilter_merge_formats(link->in_formats, link->out_formats))) {
 192                         av_log(log_ctx, AV_LOG_ERROR,
 193                                "Impossible to convert between the formats supported by the filter "
 194                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
 195                         return AVERROR(EINVAL);
 196                     }
 197                 }
 198             }
 199         }
 200     }
 201
 202     return 0;
 203 }
 204
 205 static void pick_format(AVFilterLink *link)
 206 {
 207     if (!link || !link->in_formats)
 208         return;
 209
 210     link->in_formats->format_count = 1;
 211     link->format = link->in_formats->formats[0];
 212
 213     avfilter_formats_unref(&link->in_formats);
 214     avfilter_formats_unref(&link->out_formats);
 215 }
 216
 217 static int reduce_formats_on_filter(AVFilterContext *filter)
 218 {
 219     int i, j, k, ret = 0;
 220
 221     for (i = 0; i < filter->input_count; i++) {
 222         AVFilterLink *link = filter->inputs[i];
 223         int         format = link->out_formats->formats[0];
 224
 225         if (link->out_formats->format_count != 1)
 226             continue;
 227
 228         for (j = 0; j < filter->output_count; j++) {
 229             AVFilterLink *out_link = filter->outputs[j];
 230             AVFilterFormats  *fmts = out_link->in_formats;
 231
 232             if (link->type != out_link->type ||
 233                 out_link->in_formats->format_count == 1)
 234                 continue;
 235
 236             for (k = 0; k < out_link->in_formats->format_count; k++)
 237                 if (fmts->formats[k] == format) {
 238                     fmts->formats[0]   = format;
 239                     fmts->format_count = 1;
 240                     ret = 1;
 241                     break;
 242                 }
 243         }
 244     }
 245     return ret;
 246 }
 247
 248 static void reduce_formats(AVFilterGraph *graph)
 249 {
 250     int i, reduced;
 251
 252     do {
 253         reduced = 0;
 254
 255         for (i = 0; i < graph->filter_count; i++)
 256             reduced |= reduce_formats_on_filter(graph->filters[i]);
 257     } while (reduced);
 258 }
 259
 260 static void pick_formats(AVFilterGraph *graph)
 261 {
 262     int i, j;
 263
 264     for (i = 0; i < graph->filter_count; i++) {
 265         AVFilterContext *filter = graph->filters[i];
 266
 267         for (j = 0; j < filter->input_count; j++)
 268             pick_format(filter->inputs[j]);
 269         for (j = 0; j < filter->output_count; j++)
 270             pick_format(filter->outputs[j]);
 271     }
 272 }
 273
 274 int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
 275 {
 276     int ret;
 277
 278     /* find supported formats from sub-filters, and merge along links */
 279     if ((ret = query_formats(graph, log_ctx)) < 0)
 280         return ret;
 281
 282     /* Once everything is merged, it's possible that we'll still have
 283      * multiple valid media format choices. We try to minimize the amount
 284      * of format conversion inside filters */
 285     reduce_formats(graph);
 286
 287     pick_formats(graph);
 288
 289     return 0;
 290 }
 291
 292 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
 293 {
 294     int ret;
 295
 296     if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
 297         return ret;
 298     if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
 299         return ret;
 300     if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
 301         return ret;
 302
 303     return 0;
 304 }